METHOD DEVELOPMENT, VALIDATION AND PLASMA ANALYSIS OF ETORICOXIB USING LC-MS/MS IN INDIAN HEALTHY HUMAN VOLUNTEERS

A rapid, highly sensitive, accurate and cost effective simple high performance liquid chromatographic tandem mass spectrometry (LC-MS/MS) method was developed and validated for the evaluation of cyclooxygenase-2 inhibitor etoricoxib in human plasma after administration of a single oral dose 60 mg tablet, using metoprolol as internal standard (IS). etoricoxib and metoprolol (Internal Standard) were extracted from the human plasma by protein precipitation extraction technique (PPT) by using cold acetonitrile, and separated by C18 analytical column (50 x 3 mm, particle Size- 5 μm). Both etoricoxib and IS were eluted under gradient conditions with 0.5 mL flow rate. Mobile phase consisted of 0.1% formic acid in water and 0.1% formic acid in methanol as aqueous and organic phases in pumps A and B, respectively. Detection was done by positive electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode. Chromatographic separation was obtained within 7.0 minutes and calibration curves were linear with coefficient correlation (r2) between 0.9940 to 0.9974 over a concentration range of 23.44–3000 ng/mL of etoricoxib. The method showed good extraction recoveries of etoricoxib and metoprolol from plasma ranging from 99.25% to 103.98% and 86.65% to 102.12%, respectively. Method validation evaluated parameters such as the linearity, accuracy, precision, specificity and stability, giving results within the acceptable range. The validated proposed method was successfully applied for the pharmacokinetic evaluation and bioequivalence study of this pharmaceutical product by comparing the results of test and reference samples of same concentrated dosage form by different sources with relative bioavailability 95.38% to 100%.